What is a Low Platelet Count?
Blood is made up of several types of cells. These cells float in a liquid called plasma. The types of blood cells are:
- red blood cells
- white blood cells
- platelets, or thrombocytes
When your skin is injured or broken, platelets clump together and form clots to stop the bleeding. When you do not have enough platelets in your blood, your body cannot form clots.
A low platelet count may also be called thrombocytopenia. This condition can range from mild to severe, depending on its underlying cause. For some, symptoms can include severe bleeding and are possibly fatal if not treated. Others may not experience any symptoms.
Typically, a low platelet count is the result of a medical condition, like leukemia, or certain drugs. Treatment usually addresses the condition causing the thrombocytopenia.
Causes of Low Platelet Count
There can be a few reasons why your blood does not contain enough platelets. One reason might be that your bone marrow is not forming enough platelets.
Another cause is that the body is breaking down its platelets at too fast a rate. According to the Mayo Clinic, each platelet lives about 10 days in a healthy body (Mayo Clinic, 2012.) However, some conditions might cause this life span to shorten:
Bone Marrow Problems
Your bone marrow is the spongy tissue inside the bone, where all the components of blood, including platelets, are produced. If your bone marrow is not producing enough platelets, you will have a low platelet count. Causes of low platelet production include:
- aplastic anemia
- vitamin B12 deficiency
- folate (iron) deficiency
- viral infections—including the human immunodeficiency virus (HIV), Epstein-Barr virus, and chicken pox
- exposure to chemotherapy, radiation, or toxic chemicals
- consuming too much alcohol
Low platelet count can also be a result of the body destroying too may platelets. This can be a symptom (or side effect) of:
- certain medications, include diuretics and anti-seizure medications
- hypersplenism, also known as an enlarged spleen
- autoimmune disorders
- bacterial infection in the blood
- idiopathic thrombocytopenic purpura (ITP)
- thrombotic thrombocytopenic purpura (TTP)
- hemolytic uremic syndrome
- disseminated intravascular coagulation(DIC)
Symptoms of Low Platelet Count
Whether or not you experience symptoms depends on how low your platelet count is.
Mild cases, such as when a low platelet count is caused by pregnancy, usually do not cause any symptoms. More severe cases may cause uncontrollable bleeding, which requires immediate medical attention.
If you have a low platelet count, you may experience:
- bruising that is red, purple, or brown (purpura)
- a rash with small red or purple dots (petechiae)
- bleeding gums
- bleeding from wounds that lasts a prolonged period of time or doesn’t stop on its own
- heavy menstrual bleeding
- bleeding from the rectum or blood in the stools
- blood in urine
In more serious cases, you may bleed internally. Symptoms of internal bleeding include:
- blood in your urine
- blood in your stool
- bleeding from your rectum
Talk to your doctor immediately if you experience any signs of internal bleeding.
Rarely, this condition may lead to bleeding in your brain. If you have a low platelet count and experience headaches or any neurological problems, tell your doctor right away.
Testing for and Diagnosis of Low Platelet Count
If your doctor suspects a low platelet count, he or she will first perform a physical examination. During the exam, your doctor will check your body for any unusual bruising or evidence of petechiae (the rash that often accompanies a low platelet count).
Your doctor may also feel your abdomen to check for an enlarged spleen, which can cause a low platelet count. You may also be asked if you have any family history of bleeding disorders since these types of disorders can run in families.
To diagnose this condition, your doctor needs to do a complete blood count (CBC) test. This blood test looks at the amount of blood cells in your blood. It will tell your doctor if your platelet count is lower than it should be.
Your doctor may also wish to have your blood tested for platelet antibodies. These are proteins that your body produces and that destroy platelets. Platelet antibodies can be produced as a side effect to certain drugs, such as quinine, or for unknown reasons.
Your doctor may also order blood-clotting tests, which includes partial thromboplastin time (PTT) and prothrombin time (PT). These tests simply require a sample of your blood. Certain chemicals will be added to the sample to determine how long it takes your blood to clot.
If your doctor suspects that your spleen is enlarged, he or she will order an ultrasound. This test will use sound waves to make a picture of your spleen to tell your doctor if it is the proper size.
Bone Marrow Aspiration and Biopsy
If your doctor suspects that a problem in your bone marrow is causing your low platelet count, he or she may order a bone marrow aspiration. In an aspiration, your doctor will use a needle to remove a small amount of bone marrow from one of your bones.
A bone marrow biopsy may also be ordered. This test uses a needle to take a sample of your core bone marrow, usually from the hip bone. It may be performed at the same time as a bone marrow aspiration.
Treatment for Low Platelet Count
Treatment for low platelet count depends on the cause and severity of your condition. If your condition is mild, your doctor may wish to hold off on treatment and simply monitor you.
Your doctor may recommend you take measures to prevent your condition from worsening. This could include:
- avoiding contact sports
- avoiding activities with a high risk of bleeding or bruising
- limiting alcohol consumption
- stopping or switching medications that affect platelets, including aspirin and ibuprofen
If your low platelet count is more severe, you may need medical treatment. This may include:
- blood or platelet transfusions
- changing medications that are causing low platelet count
- immune globulin
- corticosteroids to block platelet antibodies
- immune-suppressant drugs
- splenectomy, or the surgical removal of the spleen